diff --git a/ddl_ignore.txt b/ddl_ignore.txt
new file mode 100644
index 00000000000..72c0c006828
--- /dev/null
+++ b/ddl_ignore.txt
@@ -0,0 +1,3 @@
+! A list of known useful low-traffic sites are mistakenly detected as dead,
+! e.g. tools, highly specialized resources.
+! Domains must be accompanied by comments